The famous ruler was King of Rus Sviatoslav the Brave. His appearance was descibed by Byzantine court historian Leo the Deacon who met him in person in 971 AD. And what’s more, according to that Byzantine historian, that hairstyle had been worn by Sviatoslav’s anscestors as well. All the details of that encounter and new perspective on the history of Ukraine – in the “Kyiv Rus in Heimskringla Sagas and Byzantine Texts” book or, as a lighter version – in the “Gardariki, Ukraine” e-book.
